The invention relates to a coupling device comprising two tension members having mutually coacting teeth and a clamping means for keeping the toothed members in mesh with each other.
In lashing containers to the deck of a ship a pair of lashing members is often used. The members (chains or tension bars) are fastened to the deck and a container respectvely, and are tensioned and connected by means of a shroud screw or a lever arm tensioner. Shroud screws are expensive, easily damaged and slow to operate. Lever arm tensioners require high manual strength to tighten and are risky to release. Should the lashing members be tensioned by means of a separate tensioner and then in tensioned condition be coupled by means of a coupling of the type revealed in U.S. Pat. No. 1,652,677, several drawbacks would occur. The U.S. patent reveals a coupling which comprises two connector portions with toothed shanks, the teeth of which are locked in mutual engagement by means of transverse screwed connections extending through the shanks. For example, the teeth can take up a position top-to-top when the screwed connection is tightened, resulting in the risk that the lashing becomes slack or has no effect when loaded.
Before the departure of a vessel, a ship's officer, usually the second mate, must ensure that the lashings are effective, but an inspection of the known coupling devices is time-consuming, since they do not give any clear indication as to whether the teeth are mutually locked in engagement or not.
Furthermore, it takes time and energy to release and tighten the screwed connection.
Another disadvantage is that there have been difficulties in handling couplings of larger sizes/weights in connection with tensioning and releasing lashings.